diff --git a/utils/TableGen/ClangDiagnosticsEmitter.cpp b/utils/TableGen/ClangDiagnosticsEmitter.cpp
index 0f4b606808e..acaa1f8f8f5 100644
--- a/utils/TableGen/ClangDiagnosticsEmitter.cpp
+++ b/utils/TableGen/ClangDiagnosticsEmitter.cpp
@@ -162,7 +162,7 @@ void ClangDiagsDefsEmitter::run(raw_ostream &OS) {
       OS << ", \"";
       OS.write_escaped(DI->getDef()->getValueAsString("GroupName")) << '"';
     } else {
-      OS << ", 0";
+      OS << ", \"\"";
     }
 
     // SFINAE bit
@@ -275,7 +275,9 @@ void ClangDiagGroupsEmitter::run(raw_ostream &OS) {
   for (std::map<std::string, GroupInfo>::iterator
        I = DiagsInGroup.begin(), E = DiagsInGroup.end(); I != E; ++I) {
     // Group option string.
-    OS << "  { \"";
+    OS << "  { ";
+    OS << I->first.size() << ", ";
+    OS << "\"";
     OS.write_escaped(I->first) << "\","
                                << std::string(MaxLen-I->first.size()+1, ' ');